What Happened?

[DisneyGrampa]

I took my new D5000 to Disney and took a lot of pictures, trying different settings to see their effect. The first picture is at 1/400, f10. I flipped on the flash to lighten-up the close stuff and the camera slowed one stop to 1/200. It adjusted the aperture one stop to f16. I expected the far stuff in the picture to stay unchanged. But, the sky washed-out a little-why?

 

[Code]

It went down to 1/200 because that's the max sync speed of your camera.

It's the same exposure so the sky is definitely the same.. I think the difference you are seeing is due to the white balances being different. Without the flash, the auto white balance compensates for the warm tone of the evening sun, but when you use the flash the white balance is fixed to the color temp. of the flash (pure white), and thus the sunlight has a warm tint. (otherwise the fill light would have a blue tint)

 

[DisneyGrampa]

Wow-I've got a lot to learn!-thanks.
Is that white balance change based on the camera knowing it's in flash mode, or on the actual light reaching the sensor?
If I had shot in RAW, then I would have been able to set the white balance in the JPEG production process?

 

[pointandshoot]

Checked the EXIF data on your shots.

First image was at 1/400, f10, auto mode, flash not fire.
Second image was at 1/200, f14, auto mode, flash fired.

The reason the exposure changed is that you were in auto mode and it adjusted for the camera max flash synch speed. That is the fastest shutter speed, 1/200, that your flash could illuminate the subject, you.

Looks like you got 2/3 stop slower on shutter (more light) and 2/3 drop in aperature (less light).

All that said, I do not see significant difference in the two skys. What confuses me is that the poses are exactly the same and the two images were shot within 1 second of each other.

I am not sure I can pop a flash on and click that fast. What am I missing or did I read the data wrong.

EDIT: Good catch Code, white balance was different!

 

[Code]

Wow-I've got a lot to learn!-thanks.
Is that white balance change based on the camera knowing it's in flash mode, or on the actual light reaching the sensor?
If I had shot in RAW, then I would have been able to set the white balance in the JPEG production process?

I'm not familiar with your camera, but I'm assuming that it just uses flash WB when the flash is popped up and WB is on auto, otherwise it probably would have still compensated for the warmth.

And yep, RAW allows you to change the white balance before making a JPG. If the second shot was RAW, you could make it the same WB as the first, but the flash fill light would have a slightly blue tint (probably not enough to notice in this case).

Though you can also change the white balance of JPG shots too, the smaller the change, the less impact on image quality.

Looks like you got 2/3 stop slower on shutter (more light) and 2/3 drop in aperature (less light).

Those are actually 1 full stop differences.

 

[DisneyGrampa]

Checked the EXIF data on your shots.

First image was at 1/400, f10, auto mode, flash not fire.
Second image was at 1/200, f14, auto mode, flash fired.

The reason the exposure changed is that you were in auto mode and it adjusted for the camera max flash synch speed. That is the fastest shutter speed, 1/200, that your flash could illuminate the subject, you.

Looks like you got 2/3 stop slower on shutter (more light) and 2/3 drop in aperature (less light).


All that said, I do not see significant difference in the two skys. What confuses me is that the poses are exactly the same and the two images were shot within 1 second of each other.


I am not sure I can pop a flash on and click that fast. What am I missing or did I read the data wrong.



EDIT: Good catch Code, white balance was different!

I don't understand why you are referring to the change as 2/3 stop. From my SLR days, a halving of the shutter speed is a full stop, and a change of aperture by 1.4 is also a full stop.-I've been away from "serious" photograsphy for a while-has something changed?
Nope-you're reading the data correctly-I'm not familiar with other cameras, but all I have to do is hit a single button to activate the flash. I took the first picture knowing I was going to do that. One goal of this trip was to get familiar with the controls, and fast in using them.

 

[DisneySuiteFreak]

Did you shoot in Auto mode? I'm just wondering because my Exif reader says the Exposure Program is "Not Defined." I've seen others like this too, including some of my own shots. I never shoot in Auto mode, so I was wondering if it was an incidence of the mode dial being stuck between two different modes, perhaps I didn't notice it, and therefore the Exif reader software couldn't figure it out. It would help me to know if you actually shot it in Auto or not. Thanks.
In my D90 there is a way to make your flash sync speed higher. It is in the menu, called Auto FP, IIRC. I don't think the internal flash can be set any higher than 1/200 though...

 

[DisneyGrampa]

Did you shoot in Auto mode? I'm just wondering because my Exif reader says the Exposure Program is "Not Defined." I've seen others like this too, including some of my own shots. I never shoot in Auto mode, so I was wondering if it was an incidence of the mode dial being stuck between two different modes, perhaps I didn't notice it, and therefore the Exif reader software couldn't figure it out. It would help me to know if you actually shot it in Auto or not. Thanks.
In my D90 there is a way to make your flash sync speed higher. It is in the menu, called Auto FP, IIRC. I don't think the internal flash can be set any higher than 1/200 though...

I was in aout, and then auto with flash. My Nikon S/W reads it as a Scene mode, rather than an exposure mode. My Exif reader, reads the same as yours.

 

[handicap18]

I don't understand why you are referring to the change as 2/3 stop. From my SLR days, a halving of the shutter speed is a full stop, and a change of aperture by 1.4 is also a full stop.-I've been away from "serious" photograsphy for a while-has something changed?
Nope-you're reading the data correctly-I'm not familiar with other cameras, but all I have to do is hit a single button to activate the flash. I took the first picture knowing I was going to do that. One goal of this trip was to get familiar with the controls, and fast in using them.

Today's dSLR's can shoot in full, 1/2 or 1/3 stops for both shutter speed and aperture (and can also change ISO in full, 1/2 and 1/3 stops as well).

IIRC, they all default to 1/3 stops....

Full f/stops...
f/1.4, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22....

Full shutter speeds....
1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000....

If you add in the 1/3 stops...
f/1.4, 1.6, 1.8, 2, 2.2, 2.5, 2.8, 3.2, 3.6, 4, 4.5, 5, 5.6, 6.3, 7.1, 10, 11, 12.7, 14.3, 16

shutter speeds at 1/3 stop...
1/8, 1/10, 1/12, 1/15, 1/20, 1/25, 1/30, 1/40, 1/50, 1/60, 1/80, 1/100, 1/125, 1/160, 1/200, 1/250, 1/300, 1/400, 1/500, 1/640, 1/800, 1/1000....

 

[DisneyGrampa]

Today's dSLR's can shoot in full, 1/2 or 1/3 stops for both shutter speed and aperture (and can also change ISO in full, 1/2 and 1/3 stops as well).

IIRC, they all default to 1/3 stops....

Full f/stops...
f/1.4, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22....

Full shutter speeds....
1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000....

If you add in the 1/3 stops...
f/1.4, 1.6, 1.8, 2, 2.2, 2.5, 2.8, 3.2, 3.6, 4, 4.5, 5, 5.6, 6.3, 7.1, 10, 11, 12.7, 14.3, 16

shutter speeds at 1/3 stop...
1/8, 1/10, 1/12, 1/15, 1/20, 1/25, 1/30, 1/40, 1/50, 1/60, 1/80, 1/100, 1/125, 1/160, 1/200, 1/250, 1/300, 1/400, 1/500, 1/640, 1/800, 1/1000....

Thanks-but that wasn't my issue. The CHANGE from 1/400 to 1/200 is a full stop, and the corresponding CHANGE from f10 to f14 is also, approximately, a full stop. The camera changed the speed because the flash had been activated, and made a corresponding aperture change by an equal amount to keep the exposure constant. The earlier poster indicated that the CHANGE was 2/3 stop-and that is the issue I was questioning.

 

[handicap18]

Thanks-but that wasn't my issue. The CHANGE from 1/400 to 1/200 is a full stop, and the corresponding CHANGE from f10 to f14 is also, approximately, a full stop. The camera changed the speed because the flash had been activated, and made a corresponding aperture change by an equal amount to keep the exposure constant. The earlier poster indicated that the CHANGE was 2/3 stop-and that is the issue I was questioning.

Your right, they are both full stop changes. Maybe because they weren't full stop numbers he got his math confused and only thought it was a 2/3 stop change.

The sky is brighter in the second image because the shutter was open longer. Best bet to keep it the same would have been to keep your first settings (use manual) and pop the flash to fill the shadows on the subject's faces.

Even though the aperture closed a full stop it isn't necessarily going to give the exact same exposure. Its a computer chip your dealing with, not the human eye.

You also have some tough light coming in from the left. To help even further with the shadows, flip the camera so the flash points to your right instead of the left (which is more natural). That would help balance the light in the subject.

 

[VVFF]

Today's dSLR's can shoot in full, 1/2 or 1/3 stops for both shutter speed and aperture (and can also change ISO in full, 1/2 and 1/3 stops as well).

IIRC, they all default to 1/3 stops....

Full f/stops...
f/1.4, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22....

Full shutter speeds....
1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000....

If you add in the 1/3 stops...
f/1.4, 1.6, 1.8, 2, 2.2, 2.5, 2.8, 3.2, 3.6, 4, 4.5, 5, 5.6, 6.3, 7.1, 10, 11, 12.7, 14.3, 16

shutter speeds at 1/3 stop...
1/8, 1/10, 1/12, 1/15, 1/20, 1/25, 1/30, 1/40, 1/50, 1/60, 1/80, 1/100, 1/125, 1/160, 1/200, 1/250, 1/300, 1/400, 1/500, 1/640, 1/800, 1/1000....

psst....you missed F2.0.

 

[DisneyGrampa]

Your right, they are both full stop changes. Maybe because they weren't full stop numbers he got his math confused and only thought it was a 2/3 stop change.

The sky is brighter in the second image because the shutter was open longer. Best bet to keep it the same would have been to keep your first settings (use manual) and pop the flash to fill the shadows on the subject's faces.

Even though the aperture closed a full stop it isn't necessarily going to give the exact same exposure. Its a computer chip your dealing with, not the human eye.

You also have some tough light coming in from the left. To help even further with the shadows, flip the camera so the flash points to your right instead of the left (which is more natural). That would help balance the light in the subject.

Thanks-If I had a more powerful external flash, would the shadows have been filled more?
If I had increased the ISO, and decreased the speed correspondingly, would that have increased the fill effect?

 

[wenrob]

Thanks-If I had a more powerful external flash, would the shadows have been filled more?
If I had increased the ISO, and decreased the speed correspondingly, would that have increased the fill effect?

I've been reading a ton on flash lately. I'm not sure about the pop up (but I think the theory would be similar) but when using my SB600 if I were to up the ISO the power of the flash would be less as the camera and flash work together to try and get it right. I can override that if I choose by using the exposure compensation on the flash or using the flash in manual. On the D90(you may have to go through your menus to do this) you can do this with the pop up by pushing the little flash button on the camera and holding it down and then pushing the +/-. I'm not sure you can do this in Auto though. An external flash will give you more power and much more control. I've had decent success with the pop up (when I was just to lazy to carry my SB600) by using minus EC for the camera but was I fairly close to my subjects as well.

 

[Code]

Even though the aperture closed a full stop it isn't necessarily going to give the exact same exposure. Its a computer chip your dealing with, not the human eye.

Not sure what you mean here.. taking shutter speed up one stop and aperture down one will indeed give the exact same exposure.

Thanks-If I had a more powerful external flash, would the shadows have been filled more?
If I had increased the ISO, and decreased the speed correspondingly, would that have increased the fill effect?

Yes to your external flash question. It takes a lot of power to compete with the sun. At f/14, the popup flash only has an effective range of a few feet.

Increasing ISO buys you flash power when the primary light is the flash, but not when using as a fill flash against the sun. Since you are at max sync shutter speed already, any increase in ISO means you have to stop down the aperture the same amount to get the same exposure, so the ISO increase is cancelled out.

Also, a slower shutter speed will not affect the flash fill at all. The pulse of the flash is much faster than max sync shutter speed, meaning that its contribution to the exposure is fixed no matter what the shutter speed is.